Strap dispenser



Oct. 16, 1962 R. c. LUTH 3,058,689

STRAP DISPENSER Filed July 11, 1960 2 Sheets-Sheet 1 Oct. 16, 1962 R. c. LUTH 3,058,689

STRAP DISPENSER Filed July 11, 1960 2 Sheets-Sheet 2 INVENTOR.

United States Patent 3,058,689 STRAP DISPENSER Robert C. Luth, Chicago, Ill., assignor to Signode Steel Strapping Company, Chicago, 11]., 'a corporation of Delaware Filed July 11, 1960, Ser. No. 42,149 Claims. (Cl. 242-128) The present invention relates to a new and improved strap dispenser, particularly a dispenser in which strap is supplied from a mill wound coil.

Strap for binding packages, boxes, bundles, coils of wire or tubing, and the like, is supplied from the finishing mill in coils described as mill wound and ribbon wound. A mill wound coil is one having a thickness greater than the strap width, usually three to six times as thick, and wherein the strap convolutions crisscross so that the strap is evenly distributed throughout the coil. A ribbon wound coil has a thickness equal to the width of the strap, and each convolution exactly overlies the next.

From the manufacturing and original handling standpoint, mill wound coils have advantages over ribbon wound coils. In the first place it is relatively easy to produce a mill wound coil with the strap distributed relatively evenly throughout by means of a tracing finger guiding the'strap onto the takeup reel as the coil is wound. Secondly, for any given diameter a mill wound coil will have many times as much strap in it as a ribbon wound coil, and thus coils of excessively large diameter are avoided.

' On the other hand, mill wound coils have some disad vantages, particularly when they are desired for use with power strapping machines. It has been found that the inertia of such coils, particularly when they are fresh and have relatively great weight, produces a great shock on the strap feeding mechanism of the strapping machine. The crosslays or crisscrossing of the strap convolutions createa tendency of the strapping to snag as it is withdrawn from the coil. Another possibility is that rotational inertia will cause such coils to overrun when the feed to the'machine has been terminated. This overrunning leaves a substantial length of strap lying loose between the coil and the feeding mechanism of the strapping machine, which increases the opportunity for snagging.

One highly successful commercial strap dispenser is shown and described in the United States Patent No.

2,844,334, of Robert C. Luth, dated July 22, 1958, entitled Strap Dispenser. In the patented structure, a mill wound coil' is first slowly transformed into a ribbon wound coil of relatively few turns or convolutions from the center of which the strap is withdrawn by the user which may be a power strapping machine. This arrangement has been found to be very advantageous for sub stantially reducing snagging and for substantially eliminating starting shock and jerking. v

The dispenser of the present inventoin is an'improvement over the patented structure and displays a remarkably improved performance. In the improved structure of the present invention, the initial shock loading is even further reduced and it has been found that snagging has been virtually eliminated.

It is therefore an object of the present inventionto provide a new and improvednonsnagging strap dispenser wherein a mill wound coil is first converted into a ribbon wound coil of relatively few turns or convolutions and wherein the strap is withdrawn for use from the center of the ribbon wound coil, the ribbon wound coil being built up and the mill wound coil being exhausted as the strapping is withdrawn from the dispenser.

Patented Oct. 16, 1962 ice Another object is the provision of a new and improved nonsnagging strap dispenser which displays especially improved operation in the dispensing of strap of unusually small width, for example, inch.

Another object of the invention is to provide an im proved strap dispenser which is relatively universal in its use with mill wound strap of various widths.

Another object is to provide a new and improved controlled brake in a strap dispenser.

Another object is to provide a new and improved strap dispenser wherein means lift up the coils of strap as they are transferred from the mill wound coil to the ribbon wound coil to lift out any crossover coils before they can become tangled.

Another object is to provide in a strap dispenser a new and improved drive between the ribbon Winding means and the mill wound coil support means.

Another object is to provide in a strap dispenser a new and improved means maintaining the number of convolutions in the ribbon wound coil within desired limits.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a plan view of the nonsnagging strap dispenser forming the subject matter of the present invention;

FIG. 2 is a sectional elevation view taken substantially along line 22 of FIG. 1 looking in the direction of the arrows showing the improved strap dispenser;

FIG. 3 is an enlarged fragmentary plan view taken substantially along line 3-3 of FIG. 2 looking in the direction of the arrows showing the improved drive and brake means for the ribbon coil winding assembly and the mill Wound coil bearing assembly;

FIG. 4 is a fragmentary sectional elevation View along line 4-4 of FIG. 3 looking in the direction of the arrows showing certain details of the improved drive and brake means;

FIG. 5 is a fragmentary sectional elevation view showing certain details of the improved drive; and

FIG. 6 is a fragmentary plan view on a reduced scale, partially broken away, and showing convolutions of a ribbon wound coil releasing the brake.

In the drawings the dispenser 10 includes a reel 12, a mounting 14, and means 16 for stripping the strap from the center of a ribbon wound coil. The dispenser is preferably positioned with the mounting 14 in an upright position as shown in FIG. 2. V

The mounting comprises a stand or base 18 having an upstanding post 20. The upper end of the post includes axially directed, circumferentially spaced slots 21 which will be discussed later. A suitable thrust bearing 22 includes an inner race 23 which is press fit on the post 20 and rests against an annular shoulder 24. A suitable annular bearing disc 26 is press fit on and carried by the outer race 28 of the thrust bearing.

The reel 12 is a generally shallow cup-shaped element with a plurality of circumferentially spaced apertures 32 located in the base thereof. The central portion of the reel 12 has an aperture 34 within which the bearing structure 14 is received. The reel 12 is secured to the bearing disc by means of machine screws 30. Thus the bearing disc 26 and the reel 12 are rotatably carried by the bearing 22. V

The disc includes aninwardly directed flange 29 for accurate positioning of the reel in relation to the upper end of the post 20 for reasons which will be explained hereinafter. V

The stripping means '16 includes a generally disc like stripper plate 36 which abuts against the upper end of the post 20. A top spacing disc 38 is located above and generally coaxial with the stripper plate. A machine screw 40 is inserted through apertures 39 and 41 in the spacing disc and stripper plate and inserted into a threaded aperture 42 in the upper end of the post 20 for securing the disc and stripper plate to the post. As shown, the dispenser is arranged for narrower strap widths. For wider strap, the disc 38 is positioned below the stripper plate.

Frictional engagement of the stripper plate with the post 20 is sufficient to prevent rotational movement of the stripper plate in relation to the post. However, other suitable means for assuring that the stripper plate will not rotate may be provided such as that shown in Patent No. 2,844,334.

The stripper plate 36 is formed with an arcuate slot or recess 44 which subtends an angle of approximately 90. The strap being removed from the ribbon coil is pulled through the slot. At one end of the slot 44, a coiled spring strap guide 50 is suitably secured to the stripper plate by means of a fitting 52 which is welded to the plate.

The ribbon wound coil is formed on the top of an in verted generally cup-shaped intermediate ring 54 interposed between the stripper plate and the reel in generally coaxial alignment. The ring 54 includes a central aperture 56 through which the post 20 is received. The lower peripheral edge of the ring 54 rests upon the base of the reel 12.

A center disc 60 about which the ribbon wound coil is formed is carried by the intermediate ring in generally coaxial relation. The disc 60 is an annular ring with a generally rectangular cross section and is suitably secured to the upper surface of the intermediate ring by means of machine screws 62. The distance between the upper surface of the intermediate ring and the lower surface of the stripper plate is preferably less than twice the Width of the strap being dispensed to assure ribbon winding of the coil about the center disc 60. As indicated earlier, the flange 29 positions the reel 12 in relation to the upper end of the post 20. Since the intermediate ring rests on the reel and since the stripper plate is positioned by the upper end of the post (whether the spacing disc is above or below the stripper plate), the desired distance between the upper surface of the intermediate ring and the lower surface of the stripper plate is accurately fixed.

The disc 60 is milled flat along a chord at 64. A radial slot 61 is formed on the lower surface of the disc 60 between the milled end 64 and the open center of the ring. A pivot pin 68 pressed into a bore 70 projects into the slot. A latch 66 is pivotally carried by the pin 68 within the slot 61.

The latch 66 projects inwardly toward the post 20 and is notched at 72 to provide a lug 74 at the inner end of the latch. The lug 74 is adapted for latching engagement with the slots 21 in the upper end of the post 20.

The outer end of the latch 66 includes a chordal projetcion or shoe 78 secured thereto or formed thereon. The projection 78 has a recess 80 into which one end of a bias spring 82 is inserted. The other end of the spring is also received in a bore 84 in the disc 60 to urge the latch into engagement with one of the slots 21.

The vertical dimension of the latch is substantially less than that of the disc 60. The projection or shoe 78, however, has substantially the same vertical dimension as the disc. The slot 61 is of sufficient width to permit free pivotal movement of the latch 66 therein. A depending lug 79 on the projection or shoe 78 projects through a short arcuate slot 81 in the intermediate ring 54 to prevent strapping, particularly arcuate strapping, from slipping under the outer end of the latch 66.

A hearing plate 90 is fixed to the side wall of the intermediate ring. A pivot pin 92 is pressed into the bearing plate 90 and a drive latch or detent 94 is pivotally carried by the pin. A hearing washer 96 and a cotter pin 97 retain the drive latch on the pin 92. The drive latch 94 is adapted for movement into each of a plurality of circumferentially spaced circular apertures 100 in the base of the reel 12. The center of gravity of the latch 94 urges the latch toward the position in FIG. 5 when received in an aperture 100. The shoulder 101 engages the underside of the top of the ring 54 to prevent further clockwise rotation of the drive latch. One edge 102 of the latch 94 is substantially vertical in this position while the opposite edge 104 is beveled. When the latch 94 is moving toward the right (FIG. 5) relative to the reel 12, the vertical edge 102 will, when the latch drops into an aperture 100, engage the forward edge 106 of the slot to positively drive the reel with the latch. On the other hand, when the reel 12 is moving toward the right (FIG. 5) relative to the latch, the trailing edge 108 of the aperture will engage the beveled edge 104 to rotate the latch 94 out of the path of the reel. The shoulder 103 limits counterclockwise movement of the drive latch by the reel.

To prepare the dispenser for operation, the mill wound coil 17 is loaded into the empty dispenser by dropping it down into the reel 12 and disposing it around the intermediate ring 54. The restraining means, strapping or wire, (not shown), binding the mill wound coil is removed and a length of strap is taken from the center of the coil and passed around the intermediate ring 54. The length of strap is then passed completely around the center disc 60, through the guide slot 44, and through the spring strap guide 50; then it is threaded through the strapping machine or equipment (not shown) which is to use the strap.

The function of the intermediate ring is to lift up the coils of strap as they are pulled from the mill wound coil into the ribbon wound coil around the center disc, thereby to lift out any crossover coils before they become tangled underneath the stripper plate.

In first dispensing strap from the dispenser, there is not suflicient ribbon coil built up around the center disc 60 to move the projection 78 on the latch 66 radially inwardly. Hence the spring 82 will urge the latch 66 into engagement with one of the slots 21 to prevent rotation of the intermediate ring and center disc with the moving strap.

Because the dispenser is locked and prevented from rotating, the strap in being fed out will gradually build up a ribbon coil of several convolutions around the center disc 60. As many as five or six convolutions are built up in one physical embodiment of the improved structure. As the buildup increases, it will finally force the projec' tion 78 radially inwardly to disengage the latch 66 from the slots 21 permitting the intermediate ring and center disc to rotate.

As the intermediate ring and center disc begin to rotate, the latch 94 will drop into one of the apertures 100 to rotate the reel 12 with the ring and disc. As the rotational speed of the dispenser increases, the inner coils of the ribbon buildup will be fed out or loosened sufficiently to again allow the latch 66 to relock, thereby stopping any further rotation of the intermediate ring and the center disc. The reel 12 rotates the latch 94 out of its way and continues to rotate by virtue of its momentum until it coasts to a stop. The friction between the lower peripheral edge of the intermediate ring and the upper surface of the reel 12 will provide the means for reducing the reel speed.

It will be appreciated that this friction between the adjacent surfaces of the intermediate ring 54 and the reel 12 may be used to drive the reel 12 when the latch 66 is disengaged from the post 20. However, the positive drive provided by the latch 94 and the apertures 100 is the preferred method for driving the reel 12.

During normal operation of the equipment, the strapping machine may operate at a rather high rate of speed, for example, twenty cycles per minute. As a result, the reel 12 will not have sufficient time to coast to a stop. Therefore the intermediate ring 54 and the center disc 60 Will be cyclically rotated and stopped by means of the latch 66 intermittently engaging the slots 21 in the post 20. This will be the result of the ribbon wound coil cyclically building up a plurality of convolutions about the center disc 60 and to disengage the latch 66 from the slots 21 and subsequently reducing the number of convolutions to again engage the latch with the slots. The cyclical rotation of the intermediate ring 54 will provide intermittent drive to the reel 12 when the reel 12 is 1'0- tating at a slower speed than the intermediate ring. This will maintain the reel 12 within a limited speed range during operation of the strapping machine.

It will be appreciated that the improved dispenser is preferably operated with the axis of the mounting means 14 in a vertical direction as shown in FIG. 2. However, the improved dispenser may be used in other positions so long as suitable means (not shown) are utilized to retain the mill wound coil 17 in place Within the reel 12.

It will be seen from the foregoing specification that the objectives which were claimed for this invention at the outset have been attained and that a new and improved nonsnagging strap dispenser has been developed.

While the embodiment of the strap dispenser constituting this invention has been shown and described, it will be apparent that modifications and variations thereof may be made without departing from the underlying principles of the invention. It is therefore desired by the following claims to include within the scope of the invention all such variations and modifications by which substantially the results of this invention may be obtained through the use of substantially the same or equivalent means.

What is claimed as new and desired to be secured by United States Letters Patent is:

l. A strap dispenser including in combination means supported for rotation and adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of said means, structure supported for rotation about the axis of the coil supporting means and having a first surface about which a ribbon wound coil of strap may be formed by withdrawal from the center of the mill wound coil and having a second surface lifting the coils of strap as they pass from the mill wound coil to the ribbon wound coil lifting out crossover coils before they can become tangled on the structure, latch means preventing rotation of the structure and operated during withdrawal of the strap from the center of the ribbon wound coil when the ribbon wound coil builds up a plurality of convolutions to release the structure for rotation by the strap, and means connecting the structure and first mentioned means for driving the latter when its rotational speed is less than that of the structure.

2. A strap dispenser including in combination a reel supported for rotation and adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of the reel, a ring supported by and rotatable with the reel, a disc secured to the ring about which a ribbon Wound coil of strap may be formed by withdrawal from the center of the mill wound coil, the ring lifting the coils of strap as they pass from the mill wound coil to the ribbon wound coil lifting out crossover coils, latch means normally preventing rotation of the ring and disc and operated by the strap during withdrawal from the center of the ribbon wound coil when the ribbon wound coil builds up a predetermined number of convolutions to permit rotation of the ring and disc by the strap being withdrawn, the ring driving the reel when its rotational speed is less than that of the ring.

3. A strap dispenser including in combination a reel supported for rotation and adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of the reel, a ring supported by and rotatable with the reel, a disc secured to the ring and about which a ribbon wound coil of strap may be formed by withdrawal from the center of the mill wound coil, the disc rotatable by the strap upon withdrawal therefrom,

the ring lifting the coils of strap as they pass from the mill wound coil to the ribbon wound coil lifting out crossover coils before they can become tangled, latch means carried by the disc preventing and permitting rotation of the disc and ring during withdrawal of strap from the center of the ribbon wound coil when the ribbon wound convolutions are in the lower and upper parts of a selected range respectively, and a driving connection between the ring and reel.

4. A strap dispenser including in combination a reel supported for rotation and adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of the reel, a ring supported by the reel in general coaxial relation for relative rotational movement therewith, a generally circular disc secured to the ring in substantially coaxial relation therewith about which a coil of ribbon wound strap may be formed, a stationary stripper plate positioned in axially spaced relation with the ring confining the ribbon wound coil and having a slot through which strap is withdrawn from the center of the ribbon Wound coil, pivotal latch means positioned within the annulus formed by the ribbon wound coil having a normally latched position preventing rotation of the ring and disc and pivoted to an unlatched posi tion by the ribbon wound coil during withdrawal of strap from the center of the ribbon wound coil as the number of convolutions in the ribbon wound coil attain a predetermined minimum, a pivotal latch carried by the ring engaging the reel to drive the latter when reel speed is less than ring speed, the ring receiving the strap as it is trans ferred from the mill wound coil to the ribbon wound coil lifting out crossover coils before they become tangled.

5. A strap dispenser including in combination a reel adapted to support a mill wound coil of strap, means including a stand supporting the reel for rotation, a ring supported by the reel for relative rotational movement therewith, a generally circular disc secured to the ring about which a coil of ribbon Wound strap is formed by withdrawal from the center of the mill wound coil, a stationary stripper plate positioned in axially spaced relation with the ring restraining the ribbon wound coil and having a slot through which strap may be withdrawn from the center of the ribbon wound coil, latch means pivotally carried by the disc, a spring urging the latch into engagement with the stand to prevent rotation of the ring and disc and disengaged by the ribbon wound coil during withdrawal of strap while ribbon wound convolutions are greater in number than a predetermined minimum to permit rotation of the ring and disc, a pivotal latch carried by the ring engaging the reel to drive the latter when reel speed is less than ring speed, the ring receiving the strap as it is transferred from the mill wound coil to the ribbon Wound coil lifting the coils of strap to lift out crossover coils before they become tangled.

6. A strap dispenser including in combination a cupshaped reel adapted to support a mill wound coil of strap, in generally coaxial relation, an upright stand, a thrust bearing rotatably supporting the reel on the stand, an inverted cup-shaped ring supported by the reel in general coaxial relation for relative rotational movement there with, a generally circular disc secured to the ring in substantially coaxial relation therewith about which a coil of ribbon wound strap is formed by withdrawal from the center of the mill wound coil, a stationary stripper plate positioned in axially spaced relation with the ring restraining the ribbon wound coil formed about the disc and having a slot through which strap may be withdrawn from the center of the ribbon wound coil, spring-biased latch means positioned within the annulus formed by the ribbon wound coil normally engaging the stand to prevent rotation of the ring and disc and disengaged from the stand by the ribbon wound coil during withdrawal of strap from the center of the ribbon wound coil when the number of convolutions in the ribbon wound coil exceed a predetermined minimum to permit rotation of the ring and disc by the strap, a pivotal latch carried by the ring engaging the reel to rotate the reel with the ring when reel speed is less than ring speed, the ring receiving the strap as it is unwound from the mill wound coil to the ribbon wound coil lifting the coils of strap to lift out crossover coils before they become tangled with the stripper plate.

7. In a nonsnagging strap dispenser of the type in which first means is supported for rotation and is adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of said means, in which second means is supported for rotation with the first means and about which a coil of ribbon wound strap may be formed, and in which withdrawal of strap from the center of the ribbon wound coil rotates the first and second means upon the attainment of a predetermined number of ribbon wound convolutions, in combination therewith an intermediate ring interposed between the first and second means and extending from the first means beyond the mill wound coil and about which the strap moves in being transferred from the mill wound coil to the ribbon wound coil raising the coils of strap to lift out crossover coils before they become tangled.

8. In a nonsnagging strap dispenser of the type in which a reel is supported for rotation and is adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of the reel, in which a disc is supported for rotation with the reel and about which a coil of ribbon wound strap may be formed, and in which withdrawal of strap from the center of the ribbon wound coil rotates the reel and disc upon the attainment of a predetermined number of ribbon wound convolutions to maintain the number of convolutions within defined limits, in combination therewith an intermediate ring interposed between the reel and disc about which the strap moves in being transferred from the mill wound coil to the ribbon wound coil raising the coils of strap to lift out crossover coils before they become tangled on the ribbon coil, the intermediate ring extending from the reel beyond the mill wound coil to an end thereof upon which the ribbon wound coil is formed, the intermediate ring being secured to the disc and frictionally engaging the reel to rotate the ring while permitting relative rotation between the intermediate ring and the reel.

9. In a strap dispenser of the type in which a reel is supported for rotation and is adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of the reel, in which means is supported for rotation about the reel axis and about which strap withdrawn from the center of 1516 coil may be wound in ribbon coil form for withdrawal from the center thereof, and in which the means is connected to drive the reel, in combination therewith a latch mechanism connected to the means and including a bias spring urging the mechanism to a first position to prevent rotation of the means, the ribbon wound strap efiective during withdrawal while the ribbon wound convolutions are greater in number than a predetermined minimum to urge the mechanism to a second position releasing the means for rotation by the strap.

10. In a strap dispenser of the type in which first means is supported for rotation and is adapted to support a mill wound coil of strap with its axis generally parallel to the axis of rotation of the means, in which second means is supported for rotation about the axis of the first means and about which strap withdrawn from the center of the coil may be wound in ribbon form for withdrawal from the center thereof, and in which the second means is connected to drive the first means, in combination therewith a latch mechanism connected to the second means and including a bias spring urging the mechanism to a first position to prevent rotation of the second means, the rib bon wound strap effective during withdrawal while the ribbon wound convolutions are greater in number than a predetermined minimum to urge the mechanism to a second position releasing the second means for rotation by the strap.

References Cited in the file of this patent UNITED STATES PATENTS 

